Ms Twohill has been appointed senior VP of marketing at Google, joining its tightly protected California management team led by chief executive Larry Page. She joins 11 other senior VPs at the top of the organisation, whose ranks until recently boasted only one woman, YouTube head Susan Wojcicki.

Dublin City University graduate Ms Twohill, who is an 11-year Google veteran, is responsible for the biggest marketing budget in the world. Google spent around $1bn on advertising last year in the US alone.

She has been based at Palo Alto in California since she was promoted to vice president of marketing in 2009.

She joined the company's Dublin office in 2003 from travel portal Opodo. Before that she was at Bord Failte.

Though Google's most senior employees are often granted enormous stock packages, SEC filings don't reveal any Google shares in Ms Twohill's portfolio. She does, however, have 5,257 ordinary shares in US home furnishing titan Williams Sonoma, where she has been a director since 2012. She is also a director at the Telegraph Media Group.